VGA does not work with 3.0.31

[cnxsoft]

Previously I used kernel 3.0.8 and modules released with the Ubuntu 10.04 image and could enable VGA output with the following program

int main(int argc, char const *argv[])
{

unsigned long   args[4];
int             ret = -1;

int disp = open("/dev/disp", O_RDWR, 0);
args[0]         = 0;
args[1]         = 0;
args[2]         = 0;
args[3]         = 0;
ret = ioctl(disp,0x201,(unsigned long)args); //turn VGA off

args[1] = 0x4; //set mode to 1024x768
ret = ioctl(disp,0x202,(unsigned long)args); //set the mode
ret = ioctl(disp,0x200,(unsigned long)args); //turn VGA on again

return 0;

}

I've build 3.0.31 (allwinner-v3.0-android-v2) today, replaced uImage and the modules. And the program above does not seem to work anymore.

I've also got a lot of "init: Failed to create pty - disabling logging for job" messages that did not appear before. So maybe we need to enable something in the kernel that is not enabled by default.

[cnxsoft]

zgrep -i "pty" /proc/config.gz
CONFIG_UNIX98_PTYS=y

CONFIG_LEGACY_PTYS is not set

Maybe CONFIG_LEGACY_PTYS should be enabled. I'll check tomorrow if nobody has...
I'm using Linaro 12.04 rootfs btw.

[cnxsoft]

Oh well, it was just because the disp, hdmi and lcd are build as modules with the config provided in github...
so modprobe disp, modprobe hdmi fixes the video output issues. The desktop still does not show up with this kernel, so I have to investigate why.

[cnxsoft]

Adding disp, hdmi and lcd to /etc/modules fixes a "no screen" issue in Xorg.o.log, but the monitor remain black (both for HDMI and VGA), and I'm not sure what to do since I can't see errors.

[cnxsoft]

"Fixed". The modules need to be loaded in a particular order:
disp
lcd
hdmi

If hdmi is loaded before lcd, it will fail.